\[mat = 
\left( \begin{array}{cccc}
8.4 & 3.94 & 7.83 & 7.98 \\ 9.12 & 1.98 & 3.35 & 7.68 \\ 2.78 & 5.54 & 4.77 & 6.29 \\ 3.65 & 5.13 & 9.52 & 9.16 \end{array} \right) \]
